Abstract
This publication we give an overview of the activities at Fraunhofer ISE investigating SiC as an alternative to SiNx and SiOx. Our first aim was to create a conductive diffusion barrier for our Recrystallized Wafer Equivalent (RexWE). Parameters and characteristics as etch resistance, annealing behaviour (stress development, effusion of hydrogen and dopants), bandgap tuning, p- and n-doping (influence on resistivity) and diffusion behaviour were investigated. Especially the good thermal stability of our layers let us start to optimize SixC1-x as a rear-side surface passivation on p-type silicon. On a PERC structure an open-circuit voltage of 682 mV after firing at 800°C could be achieved. Further photovoltaic applications of this variable layer (single layer or stack) will be discussed.